PURPOSE: To provide a palladium plating solution, with which a high purity, stable Pd deposit appropriately used in particular as a decorative material by adding specifies amounts of pyridinecarboxylic acid, its amine based derivative and an anionic surfactant to a plating solution contg. a specified amount of a soluble Pd salt.
CONSTITUTION: The palladium plating solution comprises 1.0 to 40.0g/l of a soluble Pd salt (A), 0.1 to 10.0g/l of pyridinecarboxylic acid (B), 0.1 to 10.0g/l of an amine based derivative of pyridinecarboxylic acid (C) and 0.001 to 0.1g/l of an anionic surfactant (D). Examples of the component A are dinitrodiaminepalladium and dinitrotetraminepalladium, etc. Examples of the component B are picolinic acid, nicotinic acid and isonicotinic acid, etc. Examples of the component C are nicotinic acid amide, picolinic acid amide and isonicotinic acid amide, etc. An example of the component D is sodium di-2-ethylhexylsulfosuccinate.
ARAI YOTARO